New paper on the arxiv today! 🎉With postdoc Weikang Lin and grad student Liqiang Hou, looking at whether or not the various measurements of the Hubble constant can be reconciled: arxiv.org/abs/1910.02978 [note: technical paper]
I’ll try to write an accessible summary soon.
I’ll try to write an accessible summary soon.
Here's the key figure in the paper. It's a comparison of many different ways of measuring the Hubble constant (H0, the present-day expansion rate of the Universe) and the (present-day) matter density (Omega_m). The white circle is the region where most can sort of agree. 
The main finding of the paper is that if you look at the constraints this way, instead of just comparing on H0 by itself, you can better see that most can be reconciled, but that the local measurement from supernovae can't be. And messing with the early universe doesn't fix that.
We don't come to any conclusion about what the solution is, but our results suggest that the local measurement is really driving the tension and that if there's something going on in our region (like a local void) or some systematic with supernovae, that could point to a fix.
